O2 Sensor Positive Current Control Circuit Open (Bank 2, Sensor 1)
The P2240 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Positive Current Control Circuit Open (Bank 2, Sensor 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Poor fuel economy
- Rough idle
- Failed emissions test
- Engine running rich or lean
Probable Causes (Ranked by Likelihood)
- Failed wideband O2 sensor on Bank 2 Very High
- Open circuit in the positive current control wiring High
- Corroded connector at the wideband O2 sensor Moderate
- Damaged wiring harness near exhaust components Moderate
- ECM O2 sensor control circuit failure Low
Step-by-Step Diagnostic Procedure
-
Check for open circuits in the O2 sensor positive current control wiring
-
Inspect the Bank 2 Sensor 1 connector for corrosion or damage
-
Measure resistance in the pump cell circuit of the wideband sensor
-
Check the wiring harness for heat damage near the exhaust manifold
-
Replace the wideband O2 sensor if internal circuits have failed
Frequently Asked Questions
What is a positive current control circuit?
In wideband (air-fuel ratio) O2 sensors, the positive current control circuit manages the pump cell that measures the exact air-fuel ratio. An open circuit means the ECM cannot control this function.
Is P2240 related to a standard O2 sensor?
P2240 applies to wideband or air-fuel ratio sensors, which are more sophisticated than standard narrowband O2 sensors. They provide more precise air-fuel ratio information to the ECM.
Are wideband O2 sensors more expensive than standard sensors?
Yes, wideband sensors are typically more expensive, ranging from $80 to $250 for the part, compared to $30 to $80 for a standard narrowband sensor.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P2240 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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